Use of 1-octyl-3-methylimidazole hexafluorophosphate modified magnetic hyperbranched polyamideamine as sorbent for the extraction of pyrethroid insecticides from tea infusion.

Magnetic hyperbranched polyamideamine was carboxylated using succinic anhydride and modified further with 1-octyl-3-methylimidazole hexafluorophosphate successively. The morphology and chemical composition of the prepared material was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller measurement, and X-ray photoelectron spectroscopy, etc. 1-octyl-3-methylimidazole hexafluorophosphate modified magnetic hyperbranched polyamideamine was used as sorbent in the magnetic solid phase extraction for the separation and enrichment of 5 pyrethroid insecticides from tea infusion. The magnetic solid phase extraction method proposed in this article has low method detection limits (0.53-0.71 ng/mL), acceptable coefficient of determination (0.9992-0.9998), wide linear ranges (2.5-500.0 ng/mL), and good repeatability (intraday: 1.2-6.3%; interday: 1.6-5.4%). In the detection of 5 pyrethroid insecticides in tea infusion, relative recoveries were in the range from 87.7% to 114.7% with satisfactory relative standard deviations (0.2-7.4%). With the aid of quantum chemistry calculations, the interaction energy between the sorbent and 5 pyrethroid insecticides was calculated, which proved the necessity of the modification of 1-octyl-3-methylimidazole hexafluorophosphate. This article is protected by copyright. All rights reserved.